Solid State Sintering of Micrometric and Nanometric WC-Co Powders

Escobar J.A.,Campo F.A.,Serrano C.H. 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

A solid stage sinterizacion model of the WC-Co is applied on this work. These results are compaired with the experimental data obtained for nanometric and micrometric sinter powder in an electric furnace and micrometric in a plasma reactor (using Abnormal Glow Discharge AGD). The correlations obtained allow the prediction of the sintering behavior in AGD for nanometric powder. The activation of the solid state sintering is shown with the decraease of the WC size and the use of AGD

Shaded-Mask Filtering for Extended Depth-of-Field Microscopy

Escobar, Isabel,Saavedra, Genaro,Martinez-Corral, Manuel,Calatayud, Arnau,Doblas, Ana The Korea Institute of Information and Commucation 2013 Journal of information and communication convergen Vol.11 No.2

This paper proposes a new spatial filtering approach for increasing the depth-of-field (DOF) of imaging systems, which is very useful for obtaining sharp images for a wide range of axial positions of the object. Many different techniques have been reported to increase the depth of field. However the main advantage in our method is its simplicity, since we propose the use of purely absorbing beam-shaping elements, which allows a high focal depth with a minimum modification of the optical architecture. In the filter design, we have used the analogy between the axial behavior of a system with spherical aberration and the transverse impulse response of a 1D defocused system. This allowed us the design of a ring-shaded filter. Finally, experimental verification of the theoretical statements is also provided.

A CAD/CAM-based strategy for concurrent endodontic and restorative treatment

Escobar, Patricia Maria,Kishen, Anil,Lopes, Fabiane Carneiro,Borges, Caroline Cristina,Kegler, Eugenio Gabriel,Sousa-Neto, Manoel Damiao The Korean Academy of Conservative Dentistry 2019 Restorative Dentistry & Endodontics Vol.44 No.3

This case report describes a technique in which endodontic treatment and permanent indirect restoration were completed in the same clinical appointment with the aid of a computer-aided design/computer-aided manufacturing (CAD/CAM) system. Two patients were diagnosed with irreversible pulpitis of the mandibular first molar. After access preparation, root canals were located, irrigation was performed until bleeding ceased, and the coronal tooth structure was prepared for indirect restoration. Then, utilizing an interim 3-mm build-up of the endodontic access cavity, a hemi-arch digital scan was performed with an intraoral scanner. Subsequent to digital scanning, restoration design was performed simultaneously with the endodontic procedure. The root canals were shaped using the Race system under irrigation with 2.5% sodium hypochlorite followed by root canal filling. The pulp chamber was subsequently filled with a 3-mm-thick composite resin restoration mimicking the interim build-up previously utilized to facilitate block milling in the CAD/CAM system. Clinical try-in of the permanent onlay restoration was followed by acid etching, application of a 5th generation adhesive, and cementation of the indirect restoration. Once the restoration was cemented, rubber dam isolation was removed, followed by occlusal adjustment and polishing. After 2 years of follow-up, the restorations were esthetically and functionally satisfactory, without complications.

Evaluation of mandibular buccal shelf characteristics in the Colombian population: A cone-beam computed tomography study

Escobar-Correa, Natalia,Ramirez-Bustamante, Maria Antonia,Sanchez-Uribe, Luis Alejandro,Upegui-Zea, Juan Carlos,Vergara-Villarreal, Patricia,Ramirez-Ossa, Diana Milena The Korean Association Of Orthodontists 2021 대한치과교정학회지 Vol.51 No.1

Objective: To evaluate the mandibular buccal shelf (MBS) in terms of the angulation and bone depth and thickness according to sex, age, and sagittal and vertical skeletal patterns in a Colombian population using cone-beam computed tomography (CBCT). Accordingly, the optimal site for miniscrew insertion in this area was determined. Methods: This descriptive, retrospective study included 64 hemi-arches of 34 patients. On CBCT images, the angulation, buccal bone depth (4 and 6 mm from the cementoenamel junction [CEJ] of MBS), and buccal bone thickness (6 and 11 mm from the CEJ of MBS) were measured at the mesial and distal roots of the mandibular first and second molars. Results: There were no statistically significant differences in the angulation, depth, and thickness of MBS between male and female patients. The values for the bone around the distal root of the mandibular second molar were significantly greater than the other values. The osseous characteristics were significantly better in participants aged 16-24 years. Class III patients exhibited the best osseous characteristics, with the bone depth at 6 mm being significantly different from that in Class I and Class II patients. Although values tended to be greater in patients with low angles, the difference was not statistically significant. Conclusions: MBS provides an optimal bone surface for miniscrew insertion, with better osseous characteristics at the distal root of the mandibular second molar, 4 mm from CEJ. Adolescent patients, Class III patients, and patients with a low angle exhibit the most favorable osseous characteristics in the MBS area.

Development Of Organic-Based Sorbents For Cs+: Triumphs, Challenges, And The Way Forward

Erwin Escobar,Grace Nisola(그레이스 니솔라),John Edward Sio(존 에드워드 시오),Wook-Jin Chung(정욱진) 대한환경공학회 2021 대한환경공학회 학술발표논문집 Vol.2021 No.11

Epoxy Resins For The Selective Removal Of Cs+ In Acidic High-Level Liquid Waste

Erwin Escobar(에스코바 어윈),Grace Nisola(그레이스 니솔라),John Edward Sio(존 에드워드 시오),Wook-Jin Chung(정욱진) 대한환경공학회 2021 대한환경공학회 학술발표논문집 Vol.2021 No.11

An Intensity-Based Approach for Modeling Hedge Fung Equity

Marcos ESCOBAR,Tim FRIEDERICH,Mikhail KRAYZLER,Luis SECO,Rudi ZAGST 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

This paper analyzes an intensity-based approach for modeling hedge fund(HF) equity. We use the Cox-Ingersoll-Ross(CIR) process to describe the intensity of the HF"s default process. The intensity is purposely linked to the assets of the HF and consequently is also used to explain the equity. We examine two different approaches to link assets and intensity and derive closed-form expressions for the firms" equity in both models. We use the Kalman filter to estimate the parameters of the unobservable intensity process. The applicability of the presented methods is demonstrated on real data working with historical series from Merrill Lynch.

Thermal Desorption Spectroscopy Study of the Interaction of Hydrogen with TiC Precipitates

D. Pérez Escobar,E. Wallaert,L. Duprez,A.Atrens,K. Verbeken 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.4

Thermal desorption spectroscopy (TDS) was used to study hydrogen-trap interactions for an experimental steel (0.025 wt%C-0.09%Ti). After lab processing, the microstructure consisted of small (~20 μm) ferrite grains containing nanometer TiC precipitates. After hot and cold rolling, the material contained some hydrogen (originated from the hot rolling) in irreversible traps, the TiC precipitates. After annealing in hydrogen, the TDS spectra consisted of a high temperature peak, attributed to irreversible trapping by TiC precipitates. Annealing slightly increased the TiC precipitate size. Both the peak temperature and peak area increased with increasing annealing temperature. The increase in peak area occurred together with the increase in TiC precipitate size. The TDS spectra for samples annealed at 800 °C, and electrochemically charged, contained (i) a low temperature peak which decreased in height with increasing desorption time,and (ii) a high temperature peak that did not change significantly with desorption time, and was similar to those after gaseous charging. The low temperature peak was attributed to reversible traps such as grain boundaries, whereas the high temperature peak was attributed to irreversible trapping by TiC precipitates. The high temperature TDS peak was composed of constituent peaks with essentially the same activation energy of 145 kJ/mol.

Robotic single-site surgery: from research to clinical practice?

Pedro F. Escobar 대한부인종양학회 2011 Journal of Gynecologic Oncology Vol.22 No.2

Organic ligands for the development of adsorbents for Cs+ sequestration: A review

Erwin C. Escobar,John Edward L. Sio,Rey Eliseo C. Torrejos,Hern Kim,Wook-Jin Chung,Grace M. Nisola 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

Sorbents utilizing organic molecules as Cs+-selective ionophores have increasingly gained attention overthe years as the need for stable and reusable materials became ever more apparent with the poor performanceof inorganic sorbents in acidic and alkaline aqueous environments. Aside from this, organic moleculesoffer a great degree of flexibility in terms of structure, function, and performance which can beharnessed for sorbent development. As such, various kinds of organic ligands have been employed forsorbent preparation, which include macrocycles like calixarenes and crown ethers, and acyclic moleculeslike tetraphenylborate and resorcinol formaldehyde. In this review, organic-based sorbents and ligandsfor Cs+ are described and compared, and the mechanisms underlying their efficacy for Cs+ sequestrationare discussed. Improvements to ligand and sorbent development are proposed to address issues onadsorption selectivity, capacity, and material reusability. Moreover, a platform for the preparation ofstimuli-responsive ligands and sorbents is presented.